He is a total nut, but so much fun!! I figure no harm done, especially since he is so willing to clean himself!! I think what is most appealing thing for him is that the mud stinks!! I couldn't believe it the first time he stuck his head under the mud, but I guess it is no different than going under clean water for him. It kept the bugs (deer flies are brutal around here in the summer) off him and since the mud is heavy, it is good exercise- so why not??